The following pictures show n unit circles packed inside the smallest equilateral triangle (of side length s). Most of these have been proved optimal. When m = (n^{2}+n)/2, s = 2(n-1) + 2√3. It is conjectured that one less circle does not change this.

1.
2.
3.
s = 2√3 = 3.464+

Trivial.
s = 2 + 2√3 = 5.464+

Trivial.
s = 2 + 2√3 = 5.464+

Trivial.

4.
5.
6.
s = 4√3 = 6.928+

Proved by Milano in 1987.
s = 4 + 2√3 = 7.464+

Proved by Milano in 1987.
s = 4 + 2√3 = 7.464+

Proved by Oler/Groemer in 1961.

7.
8.
9.
s = 2 + 4√3 = 8.928+

Proved by Melissen in 1993.
s = 2 + 2√3 + 2√33/3 = 9.293+

Proved by Melissen in 1993.
s = 6 + 2√3 = 9.464+

Proved by Melissen in 1993.

10.
11.
12.
s = 6 + 2√3 = 9.464+

Proved by Oler/Groemer in 1961.
s = 4 + 2√3 + 4√6/3 = 10.730+

Proved by Melissen in 1993.
s = 4 + 4√3 = 10.928+

Proved by Melissen in 1994.

13.
14.
15.
s = 4 + 2√6/3 + 10√3/3 = 11.406+

Found by Melissen in 1993.
s = 8 + 2√3 = 11.464+

Found by Erdős/Oler in 1961.
s = 8 + 2√3 = 11.464+

Proved by Erdős/Groemer in 1961.